This invention relates generally to a vehicle transmission of the type having constant mesh gearing, and more particularly to a control assembly for effecting positive and timely shifting of the transmission.
Vehicle transmissions having an input clutch, a plurality of parallel shafts, a plurality of intermeshing gears mounted on the shafts, and a plurality of clutch collars for selectively coupling the individual gears and shafts to obtain the desired gear ratio are known. However, prior art control assemblies for such transmissions have been excessively complex and costly in construction because of the need to assure positive and timely engagement of the axially sliding clutch collars with their respectively associated clutch teeth or splines. While these clutch collars have heretofor been shifted by either manually or fluid powered shifter forks, the operator was often able to shift them out of proper phasing with the previously released or disengaged input clutch. This, of course, not only results in excessive clashing of the gear teeth but also the possibility that the respective clutch teeth are not fully engaged upon the variably timed reengagement of the input clutch. Consequently, many of these assemblies have experienced operating failures or have required frequent repair.
In view of the above, it would be advantageous to provide a simple and yet reliable transmission control assembly which would assure full release of the input clutch before allowing movement of the clutch collars and which would sense when a clutch collar is fully engaged into its proper axial position in order to positively provide a proper sequence for reengagement of the input clutch.